[tz] Tzdb build issue

[Guy Harris]

On May 31, 2023, at 12:30 AM, Naveen kumar via tz <tz at iana.org> wrote:

>     • gcc    - 4.9.4

	...

> i used the -DPORT_TO_C89 option in CFLAGS also the same error occurred. I also attached the error log also.

private.h does

	#if (__STDC_VERSION__ < 199901 && !defined restrict \
	     && (PORT_TO_C89 || defined _MSC_VER))
	# define restrict /* empty */
	#endif

before it uses the new-in-c99 "restrict" keyword.

I was able to build on Ubuntu 14.10 with GCC 4.9.1 by adding -DPORT_TO_C89 to the end of the "CFLAGS=" line in Makefile before running make; it didn't build unless I did that, as GCC 4.9.1 didn't recognize "restrict" as a keyword.

Did you add -DPORT_TO_C89 to the end of the "CFLAGS=" line in Makefile before running make?  If not, in what fashion did you use the -DPORT_TO_C89 option in CFLAGS?